A Study of 105 Patients Treated with Omalizumab for Chronic Idiopathic Urticaria

Abstract

Omalizumab (Xolair®) was approved for the treatment of chronic idiopathic urticaria in 2017. Furthermore, consistent with international guidelines published in 2018, the Urticaria Clinical Practice Guidelines by the Japanese Dermatological Association provide detailed instructions for the use of omalizumab. However, there are no reports summarizing the efficacy of omalizumab in chronic idiopathic urticaria in Japan. The subjects of our study were 105 patients treated with omalizumab 300 mg/month for chronic idiopathic urticaria at Tokyo Medical University Hospital from June 2017 to March 2021, inclusive of 23 male and 82 female patients, with a mean age of 45.4 ± 16.0 and disease duration of 46.9 ± 99.4 months. Three months after treatment, omalizumab was discontinued in 63 patients with a Urticaria Control Test score of 16. The mean number of dose completions was 6.4 ± 4.1. There were nine cases of relapse in which seven of the nine cases discontinued omalizumab within six doses. Most of the relapsed cases improved with re-administration of omalizumab, but it was again discontinued in five cases. Omalizumab has lesser side effects than steroids and cyclosporine, and the criteria for its use were revised in 2018, requiring an allergist or dermatologist to be available to treat adverse events such as asthma and anaphylaxis at the facility or in collaboration with neighboring medical institutions. Omalizumab can also be used in dermatology clinics. The drug is an effective treatment for severe chronic idiopathic urticaria and is anticipated to be used by more dermatologists.